/* ===================================================  苏畅影视传媒 - 主样式文件  Brand: 苏畅 | Domain: qczmfu.cn  =================================================== */  /* ---- CSS变量 ---- */ :root {  --primary: #1a3a5c;  --primary-light: #2a5080;  --accent: #f0a500;  --accent-light: #f5c040;  --bg-dark: #0d1f33;  --bg-mid: #f4f6f9;  --text-main: #1e2d3d;  --text-muted: #6b7c93;  --white: #ffffff;  --border: #dde3ec;  --card-shadow: 0 4px 20px rgba(26,58,92,0.10);  --radius: 12px;  --radius-sm: 6px;  --transition: all 0.3s ease;  --font-main: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif; }  /* ---- 重置 ---- */ *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; } html { scroll-behavior: smooth; font-size: 16px; } body {  font-family: var(--font-main);  color: var(--text-main);  background: var(--white);  line-height: 1.7;  overflow-x: hidden; } img { max-width: 100%; height: auto; display: block; } a { color: inherit; text-decoration: none; transition: var(--transition); } ul, ol { list-style: none; } button { cursor: pointer; border: none; background: none; font-family: inherit; }  /* ---- 排版 ---- */ h1, h2, h3, h4, h5, h6 {  font-weight: 700;  line-height: 1.3;  color: var(--primary); } h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); } h2 { font-size: clamp(1.4rem, 3vw, 2rem); } h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); } p { margin-bottom: 1em; }  /* ---- 容器 ---- */ .container {  max-width: 1200px;  margin: 0 auto;  padding: 0 20px; } .section { padding: 70px 0; } .section-alt { background: var(--bg-mid); }  /* ---- 节标题 ---- */ .section-header { text-align: center; margin-bottom: 48px; } .section-header h2 { margin-bottom: 12px; } .section-header p { color: var(--text-muted); max-width: 600px; margin: 0 auto; } .section-tag {  display: inline-block;  background: var(--accent);  color: var(--white);  font-size: 0.75rem;  font-weight: 600;  letter-spacing: 1px;  padding: 4px 12px;  border-radius: 20px;  margin-bottom: 10px;  text-transform: uppercase; }  /* ---- 按钮 ---- */ .btn {  display: inline-flex;  align-items: center;  gap: 8px;  padding: 12px 28px;  border-radius: 50px;  font-size: 0.95rem;  font-weight: 600;  transition: var(--transition);  cursor: pointer; } .btn-primary {  background: var(--accent);  color: var(--white);  box-shadow: 0 4px 15px rgba(240,165,0,0.35); } .btn-primary:hover {  background: var(--accent-light);  transform: translateY(-2px);  box-shadow: 0 6px 20px rgba(240,165,0,0.45); } .btn-outline {  border: 2px solid var(--primary);  color: var(--primary); } .btn-outline:hover {  background: var(--primary);  color: var(--white); } .btn-white {  background: var(--white);  color: var(--primary); } .btn-white:hover {  background: var(--accent);  color: var(--white); }  /* ====================================================  顶部公告栏  ==================================================== */ .top-bar {  background: var(--primary);  color: rgba(255,255,255,0.85);  font-size: 0.82rem;  padding: 7px 0; } .top-bar .container {  display: flex;  justify-content: space-between;  align-items: center; } .top-bar a { color: var(--accent); } .top-bar a:hover { color: var(--accent-light); }  /* ====================================================  导航栏  ==================================================== */ .navbar {  position: sticky;  top: 0;  z-index: 1000;  background: var(--white);  box-shadow: 0 2px 16px rgba(26,58,92,0.10);  transition: var(--transition); } .navbar.scrolled {  box-shadow: 0 4px 24px rgba(26,58,92,0.18); } .nav-inner {  display: flex;  align-items: center;  justify-content: space-between;  height: 70px;  gap: 20px; } .nav-brand {  display: flex;  align-items: center;  gap: 10px;  flex-shrink: 0; } .nav-brand img.nav-logo {  height: 44px;  width: auto;  object-fit: contain; } .nav-brand .brand-text {  font-size: 1.3rem;  font-weight: 800;  color: var(--primary);  letter-spacing: 1px; } .nav-brand .brand-text span { color: var(--accent); }  .nav-menu {  display: flex;  align-items: center;  gap: 4px; } .nav-menu a {  padding: 8px 14px;  border-radius: var(--radius-sm);  font-size: 0.92rem;  font-weight: 500;  color: var(--text-main);  white-space: nowrap; } .nav-menu a:hover, .nav-menu a.active {  color: var(--accent);  background: rgba(240,165,0,0.08); }  /* 搜索框 */ .nav-search {  display: flex;  align-items: center;  background: var(--bg-mid);  border-radius: 50px;  padding: 6px 14px;  gap: 8px;  min-width: 180px;  border: 1.5px solid transparent;  transition: var(--transition); } .nav-search:focus-within {  border-color: var(--accent);  background: var(--white); } .nav-search input {  border: none;  background: transparent;  font-size: 0.88rem;  color: var(--text-main);  outline: none;  width: 100%;  font-family: inherit; } .nav-search input::placeholder { color: var(--text-muted); } .nav-search button {  color: var(--text-muted);  font-size: 1rem;  padding: 0;  line-height: 1; } .nav-search button:hover { color: var(--accent); }  /* 搜索结果提示 */ .search-hint {  position: absolute;  top: 100%;  right: 0;  background: var(--white);  border-radius: var(--radius-sm);  box-shadow: var(--card-shadow);  padding: 12px 16px;  font-size: 0.85rem;  color: var(--text-muted);  display: none;  min-width: 220px;  z-index: 100; } .nav-search-wrap { position: relative; } .nav-search-wrap:focus-within .search-hint { display: block; }  /* 汉堡菜单 */ .nav-toggle {  display: none;  flex-direction: column;  gap: 5px;  padding: 6px;  cursor: pointer; } .nav-toggle span {  display: block;  width: 24px;  height: 2px;  background: var(--primary);  border-radius: 2px;  transition: var(--transition); }  /* 搜索栏（导航下方） */ .search-bar-below {  background: var(--bg-mid);  padding: 14px 0;  border-bottom: 1px solid var(--border); } .search-bar-below .search-form {  display: flex;  align-items: center;  max-width: 640px;  margin: 0 auto;  background: var(--white);  border-radius: 50px;  border: 2px solid var(--border);  overflow: hidden;  transition: var(--transition); } .search-bar-below .search-form:focus-within {  border-color: var(--accent);  box-shadow: 0 0 0 3px rgba(240,165,0,0.15); } .search-bar-below .search-form input {  flex: 1;  border: none;  padding: 11px 20px;  font-size: 0.95rem;  outline: none;  font-family: inherit;  color: var(--text-main);  background: transparent; } .search-bar-below .search-form button {  background: var(--accent);  color: var(--white);  padding: 11px 24px;  font-size: 0.95rem;  font-weight: 600;  font-family: inherit;  transition: var(--transition); } .search-bar-below .search-form button:hover { background: var(--accent-light); }  /* ====================================================  英雄区  ==================================================== */ .hero {  position: relative;  min-height: 560px;  display: flex;  align-items: center;  overflow: hidden;  background: var(--bg-dark); } .hero-bg {  position: absolute;  inset: 0;  background-image: url('../images/hero_banner.jpg');  background-size: cover;  background-position: center;  filter: brightness(0.45);  z-index: 0; } .hero-content {  position: relative;  z-index: 1;  color: var(--white);  max-width: 640px;  padding: 80px 0; } .hero-tag {  display: inline-block;  background: var(--accent);  color: var(--white);  font-size: 0.78rem;  font-weight: 700;  letter-spacing: 2px;  padding: 5px 14px;  border-radius: 20px;  margin-bottom: 18px;  text-transform: uppercase; } .hero-content h1 {  color: var(--white);  margin-bottom: 18px;  text-shadow: 0 2px 12px rgba(0,0,0,0.4); } .hero-content p {  font-size: 1.05rem;  color: rgba(255,255,255,0.85);  margin-bottom: 30px;  line-height: 1.8; } .hero-btns { display: flex; gap: 14px; flex-wrap: wrap; } .hero-stats {  display: flex;  gap: 36px;  margin-top: 44px;  flex-wrap: wrap; } .hero-stat-item { text-align: center; } .hero-stat-item .num {  font-size: 2rem;  font-weight: 800;  color: var(--accent);  line-height: 1; } .hero-stat-item .label {  font-size: 0.82rem;  color: rgba(255,255,255,0.7);  margin-top: 4px; }  /* ====================================================  视频卡片  ==================================================== */ .video-grid {  display: grid;  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));  gap: 24px; } .video-card {  background: var(--white);  border-radius: var(--radius);  overflow: hidden;  box-shadow: var(--card-shadow);  transition: var(--transition);  cursor: pointer; } .video-card:hover {  transform: translateY(-6px);  box-shadow: 0 12px 36px rgba(26,58,92,0.18); } .video-thumb {  position: relative;  overflow: hidden;  aspect-ratio: 16/9;  background: var(--bg-dark); } .video-thumb img {  width: 100%;  height: 100%;  object-fit: cover;  transition: transform 0.4s ease; } .video-card:hover .video-thumb img { transform: scale(1.06); } .play-btn {  position: absolute;  inset: 0;  display: flex;  align-items: center;  justify-content: center;  background: rgba(0,0,0,0.3);  opacity: 0;  transition: var(--transition); } .video-card:hover .play-btn { opacity: 1; } /* 播放按钮圆形图标 */ .play-btn::after {  content: '';  width: 60px;  height: 60px;  background: rgba(240,165,0,0.92);  border-radius: 50%;  display: block;  transform: scale(0.8);  transition: var(--transition);  box-shadow: 0 4px 20px rgba(0,0,0,0.3);  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='white'%3E%3Cpath d='M8 5v14l11-7z'/%3E%3C/svg%3E");  background-repeat: no-repeat;  background-position: center;  background-size: 36px; } .video-card:hover .play-btn::after { transform: scale(1); } .video-duration {  position: absolute;  bottom: 8px;  right: 8px;  background: rgba(0,0,0,0.7);  color: var(--white);  font-size: 0.75rem;  padding: 2px 7px;  border-radius: 4px; } .video-badge {  position: absolute;  top: 8px;  left: 8px;  background: var(--accent);  color: var(--white);  font-size: 0.7rem;  font-weight: 700;  padding: 3px 8px;  border-radius: 4px;  text-transform: uppercase; } .video-info { padding: 16px; } .video-info h3 {  font-size: 0.95rem;  margin-bottom: 8px;  display: -webkit-box;  -webkit-line-clamp: 2;  -webkit-box-orient: vertical;  overflow: hidden;  color: var(--text-main); } .video-meta {  display: flex;  align-items: center;  gap: 12px;  font-size: 0.78rem;  color: var(--text-muted);  flex-wrap: wrap; } .video-meta .views::before { content: '▶ '; } .video-meta .likes::before { content: '♥ '; color: #e74c3c; } .video-meta .comments::before { content: '💬 '; }  /* ====================================================  特色内容区  ==================================================== */ .features-grid {  display: grid;  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));  gap: 24px; } .feature-card {  background: var(--white);  border-radius: var(--radius);  padding: 28px 22px;  text-align: center;  box-shadow: var(--card-shadow);  transition: var(--transition);  border-top: 3px solid transparent; } .feature-card:hover {  transform: translateY(-4px);  border-top-color: var(--accent);  box-shadow: 0 8px 30px rgba(26,58,92,0.14); } .feature-icon {  font-size: 2.4rem;  margin-bottom: 14px;  display: block; } .feature-card h3 { font-size: 1rem; margin-bottom: 8px; } .feature-card p { font-size: 0.85rem; color: var(--text-muted); margin: 0; }  /* ====================================================  图片展示区  ==================================================== */ .gallery-grid {  display: grid;  grid-template-columns: repeat(3, 1fr);  gap: 16px; } .gallery-item {  position: relative;  border-radius: var(--radius);  overflow: hidden;  aspect-ratio: 3/4;  cursor: pointer; } .gallery-item img {  width: 100%;  height: 100%;  object-fit: cover;  transition: transform 0.4s ease; } .gallery-item:hover img { transform: scale(1.06); } .gallery-overlay {  position: absolute;  inset: 0;  background: linear-gradient(to top, rgba(13,31,51,0.8) 0%, transparent 60%);  opacity: 0;  transition: var(--transition);  display: flex;  align-items: flex-end;  padding: 16px; } .gallery-item:hover .gallery-overlay { opacity: 1; } .gallery-overlay span {  color: var(--white);  font-size: 0.88rem;  font-weight: 600; }  /* ====================================================  专家团队  ==================================================== */ .experts-grid {  display: grid;  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));  gap: 28px; } .expert-card {  background: var(--white);  border-radius: var(--radius);  overflow: hidden;  box-shadow: var(--card-shadow);  transition: var(--transition);  text-align: center; } .expert-card:hover {  transform: translateY(-5px);  box-shadow: 0 12px 36px rgba(26,58,92,0.18); } .expert-avatar {  width: 100%;  aspect-ratio: 1/1;  object-fit: cover;  object-position: top; } .expert-info { padding: 20px; } .expert-info h3 { margin-bottom: 4px; font-size: 1.05rem; } .expert-role {  color: var(--accent);  font-size: 0.82rem;  font-weight: 600;  margin-bottom: 10px; } .expert-info p { font-size: 0.84rem; color: var(--text-muted); margin-bottom: 14px; } .expert-btns { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; } .expert-btns a {  font-size: 0.78rem;  padding: 6px 14px;  border-radius: 20px;  border: 1.5px solid var(--primary);  color: var(--primary);  transition: var(--transition); } .expert-btns a:hover { background: var(--primary); color: var(--white); }  /* ====================================================  合作品牌  ==================================================== */ .partners-row {  display: flex;  flex-wrap: wrap;  gap: 20px;  justify-content: center;  align-items: center; } .partner-logo {  background: var(--white);  border: 1.5px solid var(--border);  border-radius: var(--radius-sm);  padding: 14px 28px;  font-size: 0.95rem;  font-weight: 700;  color: var(--text-muted);  transition: var(--transition);  min-width: 120px;  text-align: center; } .partner-logo:hover {  border-color: var(--accent);  color: var(--primary);  box-shadow: 0 4px 12px rgba(240,165,0,0.2); }  /* ====================================================  FAQ  ==================================================== */ .faq-list { max-width: 800px; margin: 0 auto; } .faq-item {  border: 1.5px solid var(--border);  border-radius: var(--radius);  margin-bottom: 14px;  overflow: hidden;  transition: var(--transition); } .faq-item.open { border-color: var(--accent); } .faq-question {  display: flex;  justify-content: space-between;  align-items: center;  padding: 18px 22px;  cursor: pointer;  font-weight: 600;  font-size: 0.97rem;  color: var(--text-main);  transition: var(--transition); } .faq-question:hover { color: var(--accent); } .faq-item.open .faq-question { color: var(--accent); } .faq-icon {  width: 24px;  height: 24px;  border-radius: 50%;  background: var(--bg-mid);  display: flex;  align-items: center;  justify-content: center;  font-size: 1.1rem;  flex-shrink: 0;  transition: var(--transition); } .faq-item.open .faq-icon { background: var(--accent); color: var(--white); transform: rotate(45deg); } .faq-answer {  padding: 0 22px;  max-height: 0;  overflow: hidden;  transition: max-height 0.35s ease, padding 0.35s ease;  font-size: 0.92rem;  color: var(--text-muted);  line-height: 1.8; } .faq-item.open .faq-answer { max-height: 300px; padding: 0 22px 18px; }  /* ====================================================  用户评价  ==================================================== */ .reviews-grid {  display: grid;  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));  gap: 24px; } .review-card {  background: var(--white);  border-radius: var(--radius);  padding: 24px;  box-shadow: var(--card-shadow);  transition: var(--transition);  border-left: 4px solid var(--accent); } .review-card:hover { transform: translateY(-4px); } .review-stars { color: var(--accent); font-size: 1rem; margin-bottom: 12px; } .review-text {  font-size: 0.9rem;  color: var(--text-muted);  line-height: 1.8;  margin-bottom: 16px;  font-style: italic; } .review-author {  display: flex;  align-items: center;  gap: 10px; } .review-avatar {  width: 40px;  height: 40px;  border-radius: 50%;  background: var(--primary);  display: flex;  align-items: center;  justify-content: center;  color: var(--white);  font-weight: 700;  font-size: 0.9rem;  flex-shrink: 0; } .review-name { font-weight: 600; font-size: 0.9rem; } .review-date { font-size: 0.78rem; color: var(--text-muted); }  /* ====================================================  联系我们  ==================================================== */ .contact-grid {  display: grid;  grid-template-columns: 1fr 1fr;  gap: 48px;  align-items: start; } .contact-info h3 { margin-bottom: 20px; } .contact-item {  display: flex;  gap: 14px;  align-items: flex-start;  margin-bottom: 20px; } .contact-icon {  width: 44px;  height: 44px;  background: rgba(240,165,0,0.12);  border-radius: 10px;  display: flex;  align-items: center;  justify-content: center;  font-size: 1.2rem;  flex-shrink: 0; } .contact-item .label { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 2px; } .contact-item .value { font-weight: 600; font-size: 0.95rem; } .qrcode-row {  display: flex;  gap: 24px;  margin-top: 24px;  flex-wrap: wrap; } .qrcode-item { text-align: center; } .qrcode-item img {  width: 110px;  height: 110px;  border-radius: var(--radius-sm);  border: 2px solid var(--border);  object-fit: cover; } .qrcode-item p { font-size: 0.78rem; color: var(--text-muted); margin-top: 6px; }  /* ====================================================  社交分享  ==================================================== */ .share-bar {  background: var(--primary);  padding: 20px 0; } .share-inner {  display: flex;  align-items: center;  gap: 16px;  flex-wrap: wrap; } .share-label { color: rgba(255,255,255,0.7); font-size: 0.88rem; } .share-btns { display: flex; gap: 10px; flex-wrap: wrap; } .share-btn {  display: inline-flex;  align-items: center;  gap: 6px;  padding: 7px 16px;  border-radius: 20px;  font-size: 0.82rem;  font-weight: 600;  color: var(--white);  transition: var(--transition);  border: 1.5px solid rgba(255,255,255,0.25); } .share-btn:hover { background: rgba(255,255,255,0.15); border-color: var(--accent); }  /* ====================================================  页脚  ==================================================== */ .footer {  background: var(--bg-dark);  color: rgba(255,255,255,0.75);  padding: 60px 0 0; } .footer-grid {  display: grid;  grid-template-columns: 2fr 1fr 1fr 1fr;  gap: 40px;  margin-bottom: 48px; } .footer-brand img {  height: 48px;  margin-bottom: 14px;  filter: brightness(0) invert(1); } .footer-brand p { font-size: 0.88rem; line-height: 1.8; margin-bottom: 16px; } .footer-col h4 {  color: var(--white);  font-size: 0.95rem;  margin-bottom: 16px;  padding-bottom: 10px;  border-bottom: 2px solid var(--accent);  display: inline-block; } .footer-col ul li {  margin-bottom: 9px; } .footer-col ul li a {  font-size: 0.85rem;  color: rgba(255,255,255,0.65);  transition: var(--transition); } .footer-col ul li a:hover { color: var(--accent); padding-left: 4px; } .footer-bottom {  border-top: 1px solid rgba(255,255,255,0.1);  padding: 20px 0;  display: flex;  justify-content: space-between;  align-items: center;  flex-wrap: wrap;  gap: 12px;  font-size: 0.82rem; } .footer-bottom a { color: var(--accent); } .footer-bottom a:hover { color: var(--accent-light); }  /* ====================================================  面包屑  ==================================================== */ .breadcrumb {  background: var(--bg-mid);  padding: 12px 0;  border-bottom: 1px solid var(--border); } .breadcrumb ol {  display: flex;  align-items: center;  gap: 6px;  font-size: 0.85rem;  flex-wrap: wrap; } .breadcrumb li { color: var(--text-muted); } .breadcrumb li a { color: var(--primary); } .breadcrumb li a:hover { color: var(--accent); } .breadcrumb li + li::before { content: '/'; margin-right: 6px; color: var(--border); }  /* ====================================================  页面横幅  ==================================================== */ .page-banner {  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);  padding: 60px 0;  text-align: center;  color: var(--white);  position: relative;  overflow: hidden; } .page-banner::before {  content: '';  position: absolute;  inset: 0;  background: url('../images/hero_banner.jpg') center/cover no-repeat;  opacity: 0.15; } .page-banner .container { position: relative; z-index: 1; } .page-banner h1 { color: var(--white); margin-bottom: 10px; } .page-banner p { color: rgba(255,255,255,0.8); max-width: 500px; margin: 0 auto; }  /* ====================================================  AI赋能区块  ==================================================== */ .ai-section {  background: linear-gradient(135deg, var(--bg-dark) 0%, #1a3a5c 100%);  color: var(--white);  padding: 70px 0; } .ai-section .section-header h2 { color: var(--white); } .ai-section .section-header p { color: rgba(255,255,255,0.7); } .ai-features {  display: grid;  grid-template-columns: repeat(3, 1fr);  gap: 28px; } .ai-feature {  background: rgba(255,255,255,0.07);  border: 1px solid rgba(255,255,255,0.12);  border-radius: var(--radius);  padding: 28px;  text-align: center;  transition: var(--transition); } .ai-feature:hover {  background: rgba(240,165,0,0.12);  border-color: var(--accent);  transform: translateY(-4px); } .ai-feature .icon { font-size: 2.6rem; margin-bottom: 14px; } .ai-feature h3 { color: var(--white); margin-bottom: 10px; } .ai-feature p { color: rgba(255,255,255,0.65); font-size: 0.88rem; margin: 0; }  /* ====================================================  How-To加入社区  ==================================================== */ .steps-row {  display: grid;  grid-template-columns: repeat(4, 1fr);  gap: 24px;  position: relative; } .steps-row::before {  content: '';  position: absolute;  top: 36px;  left: 12%;  right: 12%;  height: 2px;  background: var(--border);  z-index: 0; } .step-item {  text-align: center;  position: relative;  z-index: 1; } .step-num {  width: 72px;  height: 72px;  background: var(--white);  border: 3px solid var(--accent);  border-radius: 50%;  display: flex;  align-items: center;  justify-content: center;  font-size: 1.5rem;  font-weight: 800;  color: var(--accent);  margin: 0 auto 16px; } .step-item h3 { font-size: 0.97rem; margin-bottom: 8px; } .step-item p { font-size: 0.84rem; color: var(--text-muted); margin: 0; }  /* ====================================================  弹幕效果  ==================================================== */ .danmu-bar {  background: var(--bg-dark);  overflow: hidden;  padding: 10px 0;  position: relative; } .danmu-track {  display: flex;  gap: 40px;  animation: danmu-scroll 30s linear infinite;  white-space: nowrap; } .danmu-track span {  color: rgba(255,255,255,0.7);  font-size: 0.85rem;  padding: 4px 14px;  background: rgba(255,255,255,0.08);  border-radius: 20px;  flex-shrink: 0; } @keyframes danmu-scroll {  0% { transform: translateX(0); }  100% { transform: translateX(-50%); } }  /* ====================================================  统计数字  ==================================================== */ .stats-section {  background: var(--primary);  padding: 50px 0; } .stats-grid {  display: grid;  grid-template-columns: repeat(4, 1fr);  gap: 24px;  text-align: center; } .stat-item .num {  font-size: 2.4rem;  font-weight: 800;  color: var(--accent);  line-height: 1;  margin-bottom: 8px; } .stat-item .label { color: rgba(255,255,255,0.75); font-size: 0.88rem; }  /* ====================================================  响应式  ==================================================== */ @media (max-width: 1024px) {  .footer-grid { grid-template-columns: 1fr 1fr; }  .ai-features { grid-template-columns: 1fr 1fr; }  .contact-grid { grid-template-columns: 1fr; } }  @media (max-width: 768px) {  .nav-menu { display: none; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; background: var(--white); padding: 16px; box-shadow: 0 8px 24px rgba(0,0,0,0.12); z-index: 999; }  .nav-menu.open { display: flex; }  .nav-menu a { padding: 12px 16px; border-radius: var(--radius-sm); }  .nav-toggle { display: flex; }  .nav-search-wrap { display: none; }  .navbar { position: relative; }  .gallery-grid { grid-template-columns: repeat(2, 1fr); }  .steps-row { grid-template-columns: repeat(2, 1fr); }  .steps-row::before { display: none; }  .stats-grid { grid-template-columns: repeat(2, 1fr); }  .ai-features { grid-template-columns: 1fr; }  .footer-grid { grid-template-columns: 1fr; gap: 28px; }  .footer-bottom { flex-direction: column; text-align: center; }  .hero-stats { gap: 20px; }  .hero-content { padding: 60px 0; } }  @media (max-width: 480px) {  .gallery-grid { grid-template-columns: 1fr; }  .steps-row { grid-template-columns: 1fr; }  .stats-grid { grid-template-columns: repeat(2, 1fr); }  .video-grid { grid-template-columns: 1fr; }  .experts-grid { grid-template-columns: 1fr; }  .reviews-grid { grid-template-columns: 1fr; }  .features-grid { grid-template-columns: repeat(2, 1fr); } }  /* ====================================================  动画  ==================================================== */ @keyframes fadeInUp {  from { opacity: 0; transform: translateY(24px); }  to { opacity: 1; transform: translateY(0); } } .fade-in { animation: fadeInUp 0.6s ease both; } .fade-in-delay-1 { animation-delay: 0.1s; } .fade-in-delay-2 { animation-delay: 0.2s; } .fade-in-delay-3 { animation-delay: 0.3s; }  /* ====================================================  工具类  ==================================================== */ .text-center { text-align: center; } .text-accent { color: var(--accent); } .mt-20 { margin-top: 20px; } .mt-40 { margin-top: 40px; } .mb-20 { margin-bottom: 20px; } .hidden { display: none; } .flex-center { display: flex; align-items: center; justify-content: center; } .gap-10 { gap: 10px; }  /* 懒加载占位 */ img[data-src] { opacity: 1; transition: opacity 0.4s ease; background: var(--bg-dark); } img.loaded { opacity: 1; } img:not([src]) { opacity: 0; }